A Fast-Tracking Sample Preparation Protocol for Proteomics of Formalin-Fixed Paraffin-Embedded Tumor Tissues

Area of Science:

• Cancer Research
• Proteomics
• Molecular Pathology

Background:

• Archived tumor specimens preserved via formalin fixation and paraffin embedding (FFPE) are widely available.
• Despite concerns about protein cross-linking, FFPE tissues hold significant potential for proteomics discovery and targeted analysis.
• Utilizing FFPE samples integrates proteomics with existing histological and molecular pathology data, avoiding the need for additional biopsies.

Purpose of the Study:

• To evaluate the utility of FFPE tissues for proteomics in cancer research.
• To provide and benchmark an optimized protocol for protein extraction from FFPE samples, particularly for limited or precious samples.
• To support the development of spatial proteomics for investigating intratumoral heterogeneity.

Main Methods:

• Development and benchmarking of a kit-based EasyPep protein extraction method.
• Comparison against a modified filter-aided sample preparation (FASP) strategy.
• Utilized laser-capture microdissected lung adenocarcinoma tissues from a genetically engineered mouse model.

Main Results:

• Demonstrated the feasibility and effectiveness of proteomics on FFPE tissues.
• The EasyPep method was benchmarked against the FASP strategy for protein extraction efficiency and quality.
• The study provides a robust protocol suitable for analyzing FFPE samples, including those from small or precious tissue amounts.

Conclusions:

• Proteomics of FFPE tissues is a viable strategy to enhance understanding of cancer biology and clinical relevance.
• The presented protocol facilitates efficient protein extraction from FFPE samples, overcoming previous technical challenges.
• This approach enables comprehensive molecular analysis of archived tissues, leveraging existing patient data and minimizing sample requirements.